System and method for capping

ABSTRACT

A capping mechanism comprising an active feeder ( 20 ) device in which caps ( 1, 10 ) are fed actively forward arranged top-to-bottom along a feeding axis ( 30 ), and a hollow rotatable and linearly movable chuck device ( 40 ) arranged at the feeder&#39;s outlet end ( 22 ) and devised to grip a cap and mount said cap to a container opening. The feeder device preferably comprises movable members working in pairs ( 23, 24  and  25, 26  resp.) alternating to influence a row or pile of caps.

FIELD OF THE INVENTION

The present invention relates to a mechanism for capping containers, andmore particularly for a mechanism intended for applying screw-type capson containers.

BACKGROUND

Commercial distribution and sale of viscous substances are as a ruleperformed with the substance in question contained in consumer adoptedcontainers in the shape of cans, boxes, TetraPak®-type containers orbottles of different types. Most types of such containers are often insome way recloseable, e.g. by being provided with a lid for closing anopening in the container, or with a cap which can be tightly screwed toa threaded opening of the container and thereby sealing it. Differenttypes of pourable substances that are packed in this way comprisebeverages, oils, body and hair products, solvents, toners, corn flakesetc.

Consequently, capping is a frequently occurring procedure within thepackaging industry, involving a cap being mounted to an opening in acontainer. This procedure is performed just after the moment when thecontainers are filled with their content, or at an earlier stage whenthe containers themselves are produced. A known method for capping ofcontainers comprises the following steps, that generally are conductedin a repeated manner:

-   -   A cap is fed forward laying on a band, standing or rolling in a        conduit, in a chute or the like;    -   A chuck picks the cap up, alternatively the cap is fed to the        chuck;    -   The chuck lifts the cap and brings it to the opening on a        container;    -   The chuck mounts the cap on the container, e.g. by pressure or        by rotation.

Capped containers are often manufactured in very large volumes, andtherefore great effort is often made to increase production pace. Aproblem with known capping methods is that they comprise a number oftime consuming steps, limiting the capping pace. Such steps include thestep of moving the chuck from a place where the cap is picked up, to theplace where it mounts the cap on the container. Such steps also includethe step of waiting for a new cap until the gravity has worked on saidcap and caused it to fall into position for being picked up.

U.S. Pat. No. 4,222,214 to Schultz discloses a chucking apparatus forapplying caps to a threaded portion of a container at a constant torque.In a representative embodiment, caps are supplied to the apparatus by aninclined chute under the influence of gravity to a cylindrical rotatinghollow cap guide which guide caps and also conveys rotating power to achuck device, said chuck device being mounted on a lower portion of thecap guide. Caps are thus center fed to the chuck device, which devicecomprises a plurality of jaw members, each of which members arepivotable to a cap gripping position. A resilient member is arranged toengage the jaw members in response to fluid pressure, causing the jawmembers to pivot to the cap gripping position. The chuck device issubsequently rotated in order to screw the cap gripped thereby onto acontainer. The required movement of the chuck device is accomplished bylowering the chuck or raising the container or by a combination of bothmethods.

U.S. Pat. No. 1,824,660 to Darner discloses a mechanism for cappingbottles, particularly milk bottles. In an embodiment the mechanism iscentral fed with caps of the press-on type. The caps form a pile insidethe mechanism. The mechanism also comprises spiral rods, which, when themechanism is pressed down, rotates, and sharp edges of cams mounted atthe lower end of said spiral rods, separates the lowermost cap from thecaps in the rest of the pile. Comprised are also plungers that willpress the bottle cap down into a neck of the bottle.

U.S. Pat. No. 1,233,469 to Heath discloses a machine for applying caps.In one embodiment caps are applied to receptacle mouths and the machineis spinning or curling the same thereon by means of a rotary capspinning or curling device. The caps are arranged in a vertical stack orcolumn feeding downwardly by gravity through a head of the machine andaligned with an axis of rotation of said spinning device.

U.S. Pat. No. 982,231 to Barry discloses a bottle capping machine of amanual lever-operated type, comprising a magazine tube, a receptacleholder and a capping device mounted on a carrier.

U.S. Pat. No. 1495,283 to Chulin et al discloses a screw-lid fittingdevice for jars comprising a lid receiver with folding flap at top ofhollow chuck with lid stops round bottom. When the chuck comes down,upper arms of twin-arm levers disengage from endface of a cylinder. Aspring pulls the lower arms of said levers towards each other, grippingthe lid and unscrews/screws the lid as the chuck rotates.

An object of the present invention is to provide a capping mechanismcapable of providing an increased capping rate compared to the prior arttechniques. Furthermore, it is an object to provide a capping mechanismwhich can be used for various different sorts of containers and caps.

SUMMARY OF THE INVENTION

According to a first aspect, the objects according to the above arefulfilled by a capping mechanism, comprising an active feeder devicehaving means for actively feeding caps forward arranged top-to-bottomalong a feeding axis, and a chuck at an outlet end of the feeder,arranged to grip a cap and mount said cap to a container opening.Preferably, said means for actively feeding caps are devised todiametrically engage with a cap present in the feeder device, and tomove the cap forward along the feeding axis during engagement.

In one embodiment, said feeder device comprises elongated feeder membersmovable in pairs relative to each other and arranged to alternately holdand release caps arranged between two members in a pair, thereby feedingsaid caps forward during a hold and move action of at least one pair ofsaid members. Said chuck preferably has a central passage and comprisestwo or more adjustable chuck jaws arranged to hold the cap during amounting act.

The feeder members preferably comprises two pairs of feeder jaws, eachjaw of each said feeder jaw pair being moveable towards the other jaw,wherein one pair of jaws also is moveable in a direction parallel to thefeeding axis.

According to a second aspect, the objects according to the above arefulfilled by a feeder device for a capping machine, which cappingmachine comprises a chuck arranged to grip a cap and mount said cap to acontainer opening, which feeder device comprises means for activelyfeeding caps forward arranged top-to-bottom along a feeding axis, to anoutlet end proximal to the chuck. Preferably, said means for areactively feeding caps are devised to diametrically engage with a cappresent in the feeder device, and to move the cap forward along thefeeding axis during engagement. In one embodiment said feeder devicecomprises elongated feeder members movable in pairs relative to eachother and arranged to alternately hold and release caps arranged betweentwo members in a pair, thereby feeding said caps forward during a holdand move action of at least one pair of said members.

According to a third aspect, the objects according to the above arefulfilled by a method for feeding caps in a container capping machine,comprising the steps of:

-   -   supplying a cap to a feeder device;    -   engaging the cap diametrically;    -   feeding the cap, under engagement, along a feeding axis to an        outlet position.

According to a fourth aspect, the objects according to the above arefulfilled by a capping mechanism, comprising an feeder device forfeeding a cap forward, with a bottom of the cap facing a feeding axis,from an inlet position to an outlet position of said feeder device, anda chuck devised to receive a cap from a first side of said chuck at saidoutlet position, and to mount said cap to a container opening at asecond side of said chuck, opposite said first side along said feedingaxis, wherein said feeder device is devised to actively feed a cap tosaid outlet position.

Preferably, said feeder device comprises means for engaging about afirst portion of a circumference of a cap present in the feeder device,and means for moving the cap forward along the feeding axis to saidoutlet position during engagement.

In one embodiment, said chuck comprises means for engaging about asecond portion, different from said first portion, of said circumferencewhen said cap is present in said outlet position.

Preferably, said first portion covers substantially diametricallyopposing areas of the circumference of the cap.

In a preferred embodiment, said feeder device comprises first and secondgripping jaws, devised to engage a cap in said inlet position bygripping substantially diametrically opposing areas of the circumferenceof the cap, and means for moving said gripping jaws along said feedingaxis.

In one embodiment, cap supply means are devised to supply caps one byone to the inlet position of said feeder device. Said cap supply meansare preferably devised to supply caps to the inlet position in a supplydirection which has an angle to said feeding axis. In a more specificembodiment, said cap supply means are devised to supply caps to theinlet position in a supply direction which is substantiallyperpendicular to said feeding axis. Preferably, said cap supply meansare devised to supply caps arranged side-by-side along said supplydirection to the inlet position.

In a preferred embodiment, said feeder device comprises elongated feedermembers movable in pairs relative to each other and arranged toalternately hold and release a cap arranged between two members in apair, thereby feeding said cap forward during a hold and move action ofat least one pair of said members.

More specifically, in such an embodiment said feeder members may bedevised to grip and move two or more caps at a time, which caps aresuccessively supplied to said inlet position and fed top-to-bottom bysaid feeder members to said outlet position.

According to a fifth aspect, the objects according to the above arefulfilled by a method for capping containers, comprising the steps of:

-   -   supplying a cap to an inlet position of a feeder device such        that said cap is arranged with a bottom of the cap facing a        feeding axis;    -   gripping the cap by means of the feeder device engaging about a        first portion of a circumference of the cap;    -   feeding the cap, under engagement, along said feeding axis to an        outlet position;    -   receiving the cap from a first side of a chuck at said outlet        position;    -   gripping the cap by said chuck; and    -   mounting the cap to a container opening at a second side of said        chuck, opposite said first side along said feeding axis.

Preferably, said chuck grips said cap by engaging about a secondportion, different from said first portion, of said circumference.

Furthermore, said first portion preferably covers substantiallydiametrically opposing areas of the circumference of the cap.

According to a sixth aspect, the objects according to the above arefulfilled by a method for feeding caps in a container capping machine,comprising the steps of:

-   -   supplying a first and a second cap to a feeder device, wherein        said caps are arranged top to bottom;    -   engaging the caps diametrically;    -   feeding the caps, under engagement, along a feeding axis until        the first cap reaches an outlet position;    -   gripping the first cap in the outlet position with a chuck;    -   removing the first cap from the outlet position by said chuck;        and    -   feeding the second cap, under engagement, along the feeding axis        until it reaches the outlet position.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, including further features, aspects andadvantages will become better understood from the following descriptionwith reference to the accompanying drawings, on which:

FIG. 1 shows a capping mechanism according to a first embodiment of thepresent invention;

FIG. 2 shows a detail of a feeder device of the mechanism in FIG. 1,with one feeding jaw removed for enhanced clarity;

FIG. 3 shows the mechanism of FIG. 1 together with a container;

FIG. 4 shows the embodiment of FIG. 1 from the side; and

FIGS. 5–9 schematically illustrate a second embodiment of a cappingmechanism according to the invention, and different method steps of acapping process according to this embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 to 4 illustrate a first embodiment of the present invention.Referring to FIG. 1, caps 1 are supplied from above, oriented with thebottom (inside) facing left, side to side after each other, to an inletopening 21 of a feeder device 20. The caps 1 are placed in a feederdevice 20 in an inlet position 21. From this inlet position 21 caps arefed forward (left in the drawing) by the device 20, in a piledarrangement in a pipeline kind of process. A piled arrangement is notnecessarily a vertical pile, it means rather that the caps 1 arearranged top-to-bottom, i.e. the bottom of one cap faces the top of thepreceding cap, according to the drawings. Furthermore, the caps areconveyed through the feeder with the bottom facing the direction oftransportation. The feeder device 20 is also provided with an outlet end22. A feeder mechanism 23–26 is provided within the feeder device 20,devised to actively feed caps from the inlet end 21 all the way to theoutlet end 22 in a controllable pace. This feeder mechanism functions byactively gripping each cap present therein, preferably diametrically,and then displacing the cap by moving the gripping point towards theoutlet end 22. In one embodiment the feeding device comprises means forbringing caps forward with the help of a helical movement. This can beachieved by arranging two or more rotatable shafts parallel to thefeeding axis 30 and spaced from each other such that they engage a cappresent there between. The shafts can be provided with threads or thelike, such that rotation of the shafts will result in the caps beingforced forward in the feeding direction. In another embodiment thefeeding may be provided by endless belts engaging diametrically oppositesides of a cap, and running in the feeding direction.

In the shown embodiment, however, said feeder device 20 comprises twopairs of members in the form of feeding jaws. A first pair 23, 24 (24not shown in FIG. 1) and a second pair 25, 26, respectively. In thisembodiment, each pair of feeding jaws is arranged to grip caps presentthere between, preferably with a grip where said jaws make contact ondiametrically opposite sides of caps. The first pair is also shiftableback and forward in the direction of a feeding axis 30. The two pairs offeeding jaws are arranged approximately 90° in relation to each otheraround the feeding axis 30. FIG. 4 illustrates, as seen from the inletend 21, the arrangement of the feeding jaws 23–26 about the feeding axis30. The feeding jaws grip and release by relative displacement towardsand away from each other, respectively. Said jaws can grip and hold capswith the mere use of friction force, but preferably utilises a number oflugs 27 arranged for this purpose. The lugs are arranged at equidistantpositions along the feeding device 20, the distance between which isselected to fit the cap size in question. These lugs 27 will correctminor errors in alignment of the caps and prevent them from jamming thefeeder device 20.

The shown embodiment is devised to feed caps according to the followinggeneral principle:

-   -   The first pair of feeding jaws 23, 24 grips the caps in the        feeder including the one in the inlet position, while the second        pair of feeding jaws 25, 26 subsequently releases their grip        around the caps in the feeder 20;    -   The first pair of feeding jaws 23, 24 moves forward, bringing        the caps forward one positional step in the feeder along the        feeder axis towards the outlet end 22;    -   The second pair of feeding jaws 25, 26 grips the caps in the        feeder, and subsequently the first pairs of feeding jaws 23, 24        releases its grip around the caps;    -   The first pair of feeding jaws 23, 24 is brought back along the        feeding axis to enable said jaws 23, 24 to stand by for gripping        the caps and make the next cap in the inlet position 21 part of        the piled arrangement of caps in said feeder.

A cap 10 that has reached the outlet end 22 is solely held by the secondpair of feeding jaws 25, 26, and is still turned so that its bottom sidepreferably is facing outwards from the outlet end 22. With bottom sideis meant the side that is to be mounted to a container opening. FIG. 1further illustrates how a chuck 40 is arranged at the output end 22, andprovided with a central passage for the caps. The chuck preferablycomprises at least two chuck jaws 41, 42 movable in a radial directionand said chuck jaws are so devised that they can grip the cap 10 at thesame time as said cap is gripped by the second pair of feeding jaws 25,26 according to the drawing. The chuck 40 is furthermore devised torotate, for the purpose of fixing it to a container opening. For thisrotation the chuck is driven by a suitable transmission of a drive motor(not shown). FIG. 1 shows the feeder device 20 in a position subsequentto the last of the aforementioned steps. When the first pair 23,24 offeeding jaws is brought back, opposite the feeding direction, the chuck40 is displaced in the same direction along the axis 30, to a positionradially outwardly of the cap 10 held by the second feeding pair 25,26in the outlet end 22. Once in the position outside the cap 10, the chuck40 grips the cap 10 by a relative inward displacement of the chuck jaws41,42 towards the axis 30, thereby assuming the position shown inFIG. 1. When the chuck has gripped the cap 10 the second pair of feedingjaws 25, 26 are moved outwardly releasing their grip around the cap.This step also forms a part of the feeding procedure described above.The drive motor mentioned above is preferably a servo drive motorcapable of bringing the chuck 40 to an angular position that makes roomfor the second pair of feeding jaws 25, 26 in the gaps between the chuckjaws 41,42, when the chuck returns to fetch the next cap fed to theoutlet end 22.

FIG. 3 illustrates the mounting of a cap 10 to a container 50, by meansof the chuck 40. The container 50 is arranged with an opening 51 inclose proximity to, and in alignment with, the outlet end 22 and axis30. This is advantageous because the chuck 40 then only has to move thecap a minimum distance from the outlet end 22 towards the containeropening 51, clearing it from the outlet end position to which a new capis fed. This distance is completely one-dimensional and aligned with thefeeding axis 30. The power for this linear motion may come from a linearmotor, or from a suitable deflection of power from the rotation drivemotor. The radial motion of the chuck jaws 41,42 can for example beproduced by way of linear motors or pneumatics, in a manner well knownto the skilled person.

The chuck 40 is brought into a position so that during the mounting ofthe cap, said chuck can rotate freely from the pair of feeding jaws 23,24 and 25, 26, at the same time as room has been left at the outlet end22 at an outlet position in the second pair of feeding jaws 25, 26, fora new cap to be fed forward to the outlet end 22. After a completedmounting the chuck is brought back to the position shown in FIG. 3, andsaid chuck is able to repeat the described process for the next cap thathas been brought into place ready to be fed to the chuck. A newcontainer is in that connection preferably fed forward to the positionshown in FIG. 3.

FIGS. 5 to 9 illustrate a second embodiment of the present invention. Inthis embodiment, the feeder device is of a simpler design than in theprevious drawings. In this embodiment, caps are supplied from above,oriented with the bottom (inside) facing left, side to side after eachother, to an inlet position 121 of feeder device 120. The caps are e.g.supplied from a chute (not shown). In FIG. 5 a first cap 101 is placedin the inlet position 121. From this inlet position 121, cap 101 issubsequently fed forward (left in the drawing) by the device 120 to achuck 40, with the bottom of said cap 101 facing the direction oftransportation. A feeder mechanism 123,124 is provided within the feederdevice 120, devised to actively feed caps from the inlet position 21 toan outlet position 122, at which outlet position said chuck grabs thecap. This feeder mechanism functions by actively gripping each cappresent therein, preferably diametrically, and then displacing the capby moving the gripping point towards the outlet position or end 122. Inthe embodiment of FIGS. 5 to 9, the feeder mechanism of said feederdevice 120 comprises a pair of gripping members or jaws 123,124. Thepair of gripping members are arranged to grip a cap present therebetween on diametrically opposite sides of the cap. As is illustrated inFIG. 5, a front end portion of each gripping member is devised with ashoulder-like gripping portion 125 facing the other gripping member. Inthe drawing, only the gripping portion 125 of the first gripping member123 is clearly shown, but it should be noted that the second grippingmember 124 has a corresponding structure facing gripping member 123.Cooperating gripping portions 125 are devised support a cap placed inthe inlet position 121 by means of the shoulders of the grippingmembers, such that the cap will not twist but rather assume a positionwith its bottom facing the feeding axis 30. The gripping portions mayoptionally include further support structures, not only devised tosupport side and top portions of the cap, but also a front portion. Forinstance, the gripping portion 125 may include a recessed portion in therespective gripping member, providing shoulder edges both towards thetop and bottom of a cap present between the gripping members. With sucha solution, the gripping members must be capable of moving apart to anextent where the cap can be released forward along the feeding axis,when the cap has been fed to and gripped by the chuck, according to FIG.8 described in more detail below. Alternatively, the capping mechanismmay include a separate forward stopping member devised to prevent a capsupplied to the inlet position 121 to fall forward, which separateforward stopping member is withdrawn once the gripping members haveengaged and gripped the cap.

FIG. 5 illustrates a starting position, in which the first cap 101 ispositioned in the inlet position 121. A cap stopping member ispreferably arranged below the first cap 101, if the device is orientedas illustrated, such that the first cap 101 rests towards said capstopping member. The gripping jaws 123,124 are located at a distance oran angle from each other, such that the distance between grippingportions 125 is larger than the diameter of cap 101. Preferably, thenext cap 102 is does not rest on the first cap 101, but is rather fixedin the illustrated position by cap locking means (not shown). The thirdcap 103, and possibly further caps above the third, are rested one onthe other, on the second cap 102. The gripping jaws and the first cap101 are placed behind chuck 40.

FIG. 6 illustrates a second position, in which the gripping jaws havebeen placed in diametrical contact with the cap 101. This is achievedeither by displacing the gripping jaws towards each other, or bypivoting them, such that the gripping portions 125 are brought closer toeach other.

FIG. 7 illustrates how the feeder device 120 has been displaced forwardtowards the chuck, such that the first cap 101 has been brought into anoutlet position of the feeder device where it is to be handed over tothe chuck. As indicated before, the second cap 102 is maintained in theprevious position by cap locking means. As mentioned, the gripping jaws123,124 of the feeder device 120 are diametrically arranged in relationto a cap positioned there between. Furthermore, as is also illustratedin the drawings, the gripping portions 125 of the gripping jaws eachcover only a first portion of the circumference of the cap. The chuck,on the other hand, comprises at least two chuck jaws 41, 42 which aredisplaceable in a radial direction from a centre feeding axis 30, seeFIG. 5. These chuck jaws each cover a second portion of thecircumference of the cap. The first and second portions of thecircumference are complementary, and together they cover, at most, theentire circumference, though preferably less. Furthermore, when thecapping mechanism is arranged in the position as shown in FIG. 7, thechuck jaws are rotatably oriented such that the gripping jaws 123,124and the chuck jaws 41,42 face different portions of the circumference ofthe cap. This way, both the gripping jaws 123,124 and the chuck jaws41,42 are capable of gripping the cap, preferably perpendicularly inrelation to each other.

FIG. 8 illustrates how the chuck jaws 41,42 have been displaced radiallyinwards, to grip the first cap 101. Once the cap 101 has been gripped bythe chuck jaws, the gripping jaws 123,124 of the feeder device 120release their grip of the cap, and the gripping jaws are brought back tothe position shown in FIG. 5.

FIG. 9 illustrates application of the cap on a container opening (notshown). The cap 101 is applied by rotation of chuck 40. At the sametime, the chuck is preferably displaced forward towards the containeropening at a rate corresponding to the pitch of cooperating threads onthe inside of the cap and on the outside of the container opening,respectively, such that the container opening can be maintained in asubstantially fixed position during application of the cap. In apreferred embodiment, rotation of chuck 40 also unlocks the cap lockingmeans, such that the subsequent cap 102 enters the inlet position 121.When the first cap 101 has been applied, chuck 40 returns the positionof FIG. 6, preferably by first releasing its grip of the first cap 101,thereafter by rotating to the perpendicular orientation in relation tothe gripping jaws 123,124, and finally by a backwards lineartranslation. The capping mechanism is then returned to the stateillustrated in FIG. 5, and the process is thereafter preferablyrepeated, including the steps of removing the capped container openingand placing a new container opening in front of chuck 40.

Several advantages are achieved with the present invention. It should benoted that many of the above actions performed by the participatingparts can take place simultaneously, forming an efficient pipeline, orassembly-line way of operation of the capping mechanism, enabling a highcapping pace. The feeding and the transport in the chuck of the cap takeplace in one and the same dimension, which results in a simple andthereby fail-safe process. Moreover, the displacement of the chuck 40 isvery short, in the described embodiment basically not longer than theheight of a cap or the pitch of the threaded portion of the cap, whichenables an increased pace of capping compared to a solution in which thecap has to be picked up by the chuck and be transported sideways,compared to axis 30, to the container opening 51. The feature of feedingthe caps top-to-bottom also enables, in most cases, a more compactdesign of the capping machine including the feeding device.

A technical effect of the present invention is that the feeding of capsdoes not rely on gravity. The supply of caps to the feeder device mayrely on gravity, but may alternatively be achieved by actively supplyingthe caps by force to the feeder device. This means that the feedingapparatus, combined with a chuck, can be used for applying caps in anydirection. It is well known that there are several types of containerswhich have side-mounted openings, e.g. the type illustrated in FIG. 3,suitable for water closet cleaning fluids. This type of container cannotbe capped by any of the aforementioned gravity-dependent solutions ofthe prior art. The use of gravity feeding further has the disadvantagethat flat caps tend to jam in a feeding pipe if they are dropped top tobottom. Furthermore, some types of caps are conical, such that the topof one cap fits into the bottom of another cap. Both the weight of thecaps and the fact that they are repeatedly dropped and halted, may causethem to engage and catch on to each other when arranged piled top tobottom.

In the shown embodiment, the cap is mounted by rotation into threadedengagement with the container opening 51. However, it could of coursealso be advantageous to use the present invention on a push- orpress-cap container design, suitable for a capping device where thechuck is arranged for example to push the capsule on to the containeropening. A person skilled in the art also realises that the container onto which the cap is mounted is not necessarily a complete container, butalternatively only that part of the container on to which the containeropening is formed, e.g. a bottle neck. The foregoing has described theprinciples, preferred embodiments and modes of operation of the presentinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. It should beappreciated that variations may be made in those embodiments by workersskilled in the art without departing from the scope of the presentinvention as defined by the following claims.

1. A capping mechanism, comprising a feeder device for feeding capsforward arranged top-to-bottom along a feeding axis to an outletposition said feeder device, and a chuck arranged to grip a cap from afirst side of said chuck at said outlet position, and to mount said capto a container opening at a second side of said chuck, opposite saidfirst side along said feeding axis, wherein said feeder device comprisesmeans for engaging diametrically about a cap present in the feederdevice, and means for moving the cap forward along the feeding axis tosaid outlet position during engagement, wherein said chuck comprisesmeans for engaging said cap in said outlet position.
 2. The mechanism asrecited in claim 1, wherein said feeder device comprises a pair offeeder jaws devised to alternately grip and release a cap present therebetween, and to feed the cap forward by displacing said pair of feederjaws forward along the feeding axis during engagement.
 3. The mechanismas recited in claim 2 wherein said feeder device comprises elongatedfeeder members movable in pairs relative to each other and arranged toalternately hold and release caps arranged between two members in apair, thereby feeding said caps forward during a hold and move action ofat least one pair of said members.
 4. The mechanism as recited in claim3, wherein said chuck has a central passage and comprises two or moreadjustable chuck jaws arranged to hold the cap during a mounting act. 5.The mechanism as recited in claim 3, wherein said feeder memberscomprises two pairs of feeder jaws.
 6. The mechanism as recited in claim5, wherein each jaw of each pair of feeder jaws is moveable towards theother jaw, and in that one pair of jaws also is moveable in a directionparallel to the feeding axis.
 7. The mechanism as recited in claim 1,wherein said feeder device comprises elongated feeder members movable inpairs relative to each other and arranged to alternately hold andrelease caps arranged between two members in a pair, thereby feedingsaid caps forward during a hold and move action of at least one pair ofsaid members.
 8. The mechanism as recited in claim 7, wherein said chuckhas a central passage and comprises two or more adjustable chuck jawsarranged to hold the cap during a mounting act.
 9. The mechanism asrecited in claim 7, wherein said feeder members comprises two pairs offeeder jaws.
 10. The mechanism as recited in claim 9, wherein each jawof each pair of feeder jaws is moveable towards the other jaw, and inthat one pair of jaws also is moveable in a direction parallel to thefeeding axis.
 11. The capping mechanism as recited in claim 1, whereinsaid feeder device comprises means for engaging about a first portion ofa circumference of a cap present in the feeder device, and said chuckcomprises means for engaging about a second portion, different from saidfirst portion, of said circumference when said cap is present in saidoutlet position.
 12. The capping mechanism as recited in claim 11,wherein said first portion covers substantially diametrically opposingareas of the circumference of the cap.
 13. The capping mechanism asrecited in claim 11, wherein said feeder device comprises first andsecond gripping jaws, devised to engage a cap in said inlet position bygripping substantially diametrically opposing areas of the circumferenceof the cap, and means for moving said gripping jaws along said feedingaxis.
 14. The capping mechanism as recited in claim 1, wherein capsupply means are devised to supply caps one by one to the inlet positionof said feeder device.
 15. The capping mechanism as recited in claim 14,wherein said cap supply means are devised to supply caps to the inletposition in a supply direction which has an angle to said feeding axis.16. The capping mechanism as recited in claim 15, wherein said capsupply means are devised to supply caps to the inlet position in asupply direction which is substantially perpendicular to said feedingaxis.
 17. The capping mechanism as recited in claim 14, wherein said capsupply means are devised to supply caps arranged side-by-side along saidsupply direction to the inlet position.
 18. The capping mechanism asrecited in claim 14, wherein said feeder device comprises elongatedfeeder members movable in pairs relative to each other and arranged toalternately hold and release a cap arranged between two members in apair, thereby feeding said cap forward during a hold and move action ofat least one pair of said members.
 19. The capping mechanism as recitedin claim 1, wherein said feeder device is arranged to grip and move twoor more caps at a time, which caps are successively supplied to saidinlet position and fed top-to-bottom by said feeder members to saidoutlet position.
 20. A method for capping containers, comprising thesteps of: supplying a cap to an inlet position of a feeder device suchthat said cap is arranged with a bottom of the cap facing a feedingaxis; gripping the cap by means of the feeder device engaging about afirst portion of a circumference of the cap; feeding the cap, underengagement, along said feeding axis to an outlet position; receiving thecap from a first side of a chuck at said outlet position; gripping thecap by said chuck; and mounting the cap to a container opening at asecond side of said chuck, opposite said first side along said feedingaxis.
 21. The method for capping containers as recited in claim 20,wherein said steps of gripping and feeding the cap in the feeder deviceis executed by the steps of: gripping said cap with a pair of feederjaws; and displacing said pair of feeder jaws forward along the feedingaxis.
 22. The method for capping containers as recited in claim 20,wherein said chuck grips said cap by engaging about a second portion,different from said first portion, of said circumference.
 23. The methodfor capping containers as recited in claim 22, wherein said firstportion covers substantially diametrically opposing areas of thecircumference of the cap.
 24. A method for feeding caps in a containercapping machine, comprising the following steps: supplying a first and asecond cap to a feeder device, wherein said caps are arranged top tobottom; engaging the caps diametrically; feeding the caps, underengagement, along a feeding axis until the first cap reaches an outletposition; gripping the first cap in the outlet position with a chuck;removing the first cap from the outlet position by said chuck; andfeeding the second cap, under engagement, along the feeding axis untilit reaches the outlet position.